/*
 * Copyright 2019 Flipkart Internet Pvt. Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.flipkart.ohos.proteus.value;

import com.flipkart.ohos.proteus.ProteusConstants;

/**
 * Null
 *
 * @author aditya.sharat
 */
public class Null extends Value {
    /**
     * singleton for JsonNull
     *
     * @since 1.8
     */
    public static final Null INSTANCE = new Null();

    private static final String NULL_STRING = "NULL";

    @Override
    public Null copy() {
        return INSTANCE;
    }

    @Override
    public String toString() {
        return NULL_STRING;
    }

    @Override
    public String getAsString() {
        return ProteusConstants.EMPTY;
    }

    /**
     * All instances of Null have the same hash code
     * since they are indistinguishable
     *
     * @return return
     */
    @Override
    public int hashCode() {
        return Null.class.hashCode();
    }

    /**
     * All instances of JsonNull are the same
     *
     * @param other other
     * @return return
     */
    @Override
    public boolean equals(Object other) {
        return this == other || other instanceof Null;
    }
}
